The invention relates to a method and an apparatus for producing pipes or similar tubular molded objects from polymer concrete. The invention furthermore relates to a polymer concrete socket pipe.
In practice, for the production of pipes from polymer concrete, molding equipment is used, which consists of a mold core and a mold casing, which together form the boundary of a molding space. The molding space of the molding equipment, the main axis of which is aligned vertically, is filled with a mineral casting composition by means of filling equipment and this mineral casting composition is subsequently shaken as a whole. Sometime after the end of the shaking process, the mineral casting composition, which is at ambient temperature, commences to cure. After the curing process is largely concluded, the molding equipment casing is removed from the molded object. Since the pipe shrinks as it cures and, during the slow course of the curing process, the casing cannot be removed from the pipe before considerable shrinkage occurs, a sleeve-like compensating body, which then lines the finished pipe as a liner, must be placed on the mold core.
In the case of a method of an older proposal (P 43 39 118.4), the molded object is built up sectionwise along its central axis by filling consecutive longitudinal sections of the molding space of the molding equipment with mineral casting composition and shaking the mineral casting composition in the filling region and is cured sectionally phase-offset in the same direction. For this purpose, the molding equipment has a mold casing of superimposed, transposable casing segments, the segment parts of which in each case can be moved apart from an annular, closed operating position into nonoperative position and transposed in this position. The mold core is divided into axially limited sections, which form different treatment zones, it being possible to move the mold casing and mold core relative to one another in the axial direction during the production of a molded object.
It is an object of the invention to provide a method and an apparatus for producing molded objects, particularly a socket pipe, from polymer concrete. The method and apparatus are to enable tubular molded objects to be produced from polymer concrete with little operational and structural expense.
The invention enables pipes and tubular molded objects to be produced with a continuous or quasi continuous formation of the molded object in a molding space, which is stationary at least in the main part and which is traversed by the column of mineral casting composition. At the same time, the column of material is molded, solidified and cured. The structural expense of the molding equipment is exceedingly low, so that advantageous operating processes as well as simple retrofitting possibilities arise for the production of molded objects of different dimensions.
Further advantages and details of the invention arise out of the following description and the drawing, in which two examples of inventive molding equipment are shown diagrammatically.
FIG. 1 shows a side view of a first embodiment of the inventive molding equipment, partially in section, in a basic position before the start of the manufacturing process,
FIG. 2 shows a side view, half in section, similar to that of FIG. 1 to illustrate parts of an initial phase of the production of the molded body,
FIG. 3 shows a side view similar to that of FIG. 1 to illustrate the parts at the conclusion of the manufacturing process of a molded object,
FIG. 4 shows a partial, truncated, longitudinal section through a length region of the upper part of the mold casing,
FIG. 5 shows a section along the line Vxe2x80x94V of FIG. 4,
FIG. 6 shows a partial, truncated, longitudinal section, similar to that of FIG. 4, through the lower end of the molding space,
FIG. 7 shows a diagrammatic plan view of the closing part with mold segments as inner mold for the socket part,
FIG. 8 shows a representation of a further embodiment of the inventive molding equipment,
FIG. 9 shows a sectional enlargement of FIG. 8 with a closing body in a starting position at the commencement of the manufacturing process,
FIG. 10 shows a representation similar to that of FIG. 8 to illustrate the molding equipment in a later phase of the operation,
FIG. 11 shows an enlarged sectional representation of the molding equipment of FIG. 8 to illustrate positions of the molding body in the process of formation while severing the film curtains, during the introduction of the intermediate supporting elements and after assumption of the support by these,
FIG. 12 shows a representation similar to that of FIG. 11 to illustrate positions of the molded object in the process of formation in consecutive phases of the continuous production process,
FIGS. 13 and 14 show enlarged sectional representations of the molding equipment of FIG. 8 for a more detailed diagrammatic representation of the interior tool of the film-severing equipment in two mutually orthogonal viewing directions,
FIGS. 15 and 16 are representations similar to those of FIGS. 13 and 14 to illustrate the exterior tool of the film-severing equipment and its support as well as the support of the intermediate supporting elements,
FIG. 17 shows a section along the line XVIIxe2x80x94XVII of FIG. 15,
FIG. 18 shows a representation similar to that of FIG. 12 to illustrate the position of a finished molded object directly before it is discharged from the molding equipment,
FIG. 19 shows a diagrammatic plan view of discharging equipment for finished molded bodies, and
FIGS. 20 to 22 show truncated cross-sectional representations of socket pipes in a two-part construction.